2015 Subaru WRX STI Review and Design

This is the all-new 2015 Subaru WRX STI - a four-wheel drive, four-door-only widebody, with 305 horsepower and 290lb ft, revealed at this year's Detroit motor show. Powered by the legendary 305-horsepower 2.5-liter turbocharged BOXER engine, the 2015 WRX STI debuts a new four-door wide-body design, built on a stiffer chassis for even greater handling agility and precision. The Subaru WRX STI provides a rally-bred drivetrain and all-wheel drive handling that is unique to this model. Handling is enhanced with a stiffer chassis, firmer springs and faster steering (13.0:1 ratio). 

For 2015, the new STI is built on a stiffer chassis and hits the road with a new wide-body design and interior upgrades that include Alcantara upholstery. What Subaru calls a "nose cone" frontal design combines the front bumper and grille into a single unit, framed by narrow headlights with LED low beams. The hood is made of aluminum to reduce weight, and its scoop feeds air to the turbo intercooler. The hood is one of many body panels and components distinct to the STI model, including the fenders, doors, quarter panels, bumpers, and rear LED taillight clusters. Front fender vents are covered with mesh screens, and the fog lights are surrounded with a pattern reminiscent of carbon fiber. The traditional STI large trunk spoiler finishes off the body. The 2015 Subaru WRX STI is powered by a 2.5-liter turbocharged/intercooled 4-cylinder BOXER engine that employs the Dual Active Valve Control System (Dual AVCS). The engine, which is exclusive to the STI model, produces 305 horsepower (SAE) at 6,000 rpm and 290 lb.-ft. of peak torque at 4,000 rpm.

At the ground, larger 18-inch forged BBS wheels are wrapped in wider 245-series summer performance tires for even more grip than the already Velcro-like WRX. Behind the gold shoes are big Brembo four-piston front and two-piston rear calipers. Brake rotors are 13 inches and 12.4 inches at the front and rear, respectively. Unlike the standard WRX, the STI's front wheels are still actuated by a hydraulic power-assist rack rather than electric. With more motor, bigger brakes, and fatter tires, not to mention an STI-tuned suspension, expect all performance metrics to improve despite the number of carryover parts. We expect the STI to hit 60 mph in five seconds or less and run the quarter mile in the low 13-second range. Lateral acceleration may well scratch a full 1.0 g, and the figure-eight time should drop to near 25 seconds flat. Braking may well drop below the 100-foot mark.